The purpose of this study was to clarify the effects of bicycle ergometer training and prostaglandin E₁ (PGE₁) for patients with intermittent claudication. Subjects were divided into four groups : the medication group (M), the PGE₁ group (P), the exercise group (E) and the PGE₁ and exercise group (PE). The P group was injected with 10μg of PGE₁, the E group performed bicycle ergometer exercise 3 times a week for 6 weeks, and the PE group was injected with PGE₁ and performed exercises. The maximal walking distance (MWD) was evaluated by a treadmill test. Muscle oxygenation level was measured by near-infrared spectroscopy and recovery half time (T_1/2) was calculated. MWD was significantly improved for P (142%), E (216%) and PE (240%) groups. T_1/2 was significantly improved in the E and PE groups. This study indicates that improvement of MWD was a result of development of muscle perfusion in lower limbs and PGE₁ injection may support exercise therapy.

Patients with mechanical valve prosthesis must receive long-term oral anticoagulant therapy, thus it is important to set the optimal international normalized ratio of prothrombin time (PT-INR) that effectively prevented thromboembolic complications without excessive bleeding. In this study, anticoagulant therapy was evaluated in terms of the activity of coagulation and fibrinolysis in 137 patients after isolated mechanical valve replacement. With a lower target range of 1.5-2.0 for the PT-INR, thrombin antithrombin III complex (TAT) increased to more than 3.0ng/ml in 30 cases, and the activity of coagulation appeared to increase due to insufficient anticoagulant therapy. After the target range was raised to 2.0-2.5 in all cases, the PT-INR increased significantly from 1.63 to 2.25 (p<0.01) and TAT decreased significantly from 7.58 to 2.81ng/ml (p<0.01). This showed that activity of coagulation and fibrinolysis was suppressed by high intensity anticoagulation. It is necessary to review the individual activity of coagulation and fibrinolysis to determine the intensity of anticoagulation. We recommend 2.0-2.5 as the target range for the PT-INR.

Infra-renal abdominal aortic aneurysms were electively treated by bifurcated endovascular stent grafts (Power Web^TM system, Endologix Co., USA) at 5 Japanese centers. The stent grafting (SG) was applied for candidates nominated by the selection committee after informed consent was obtained according to the IRB in each center. The delivery success rate of 60 patients (53 males) was 96.7%. There were 2 patients with type I endoleaks, resulting in a technical success rate of 93.3%. The operation time of 193±55min and blood loss of 440±240g were significantly shorter and less, respectively in the SG group when compared with 303±88min and 1, 496±2, 025g in 97 patients (83 males) treated by conventional open surgery. Endoleaks were detected in 4 patients (type I: 3, type II: 1) by CT scan taken at the time of discharge or 1 month after SG procedure. Type I endoleak was observed in patients with short and severely angulated SG landing zones. Renal artery obstruction, and temporary buttock pain caused by internal iliac artery occlusion occurred, but there was no hospital death. In 56 patients excluding an SG-unrelated death and a dropout from surveillance, there was no secondary endoleak or marked adverse events at all except 1 SG limb occlusion during a 6-month follow up period. The aneurysm size shrank in 26 patients and remained unchanged in 30 patients. No aneurysm enlargement was observed. The Power Web^TM system is appropriate for minimally invasive surgery for abdominal aortic aneurysms. Long-term follow-up studies will follow.

Postoperative quantitative evaluation of left internal thoracic artery (LITA) grafts is usually performed by angiography, scintigraphy and Doppler flowire. However it is difficult to observe the characteristics of the intima of the LITA graft. The purpose of this study was to evaluate the characteristics and quantity of plaque of intima of LITA grafts in 6 cases after coronary artery bypass surgery using an intra-vascular ultrasound device (IVUS). There was no stenosis or calcification of LITA grafts on angiography. However we found atherosclerotic plaque in all LITA grafts by IVUS. Characteristics of plaque were eccentric in all cases, and soft, hard and mixed plaque were found. The average minimal lumen diameter of LITA grafts was 2.6±0.2mm. The average lumen area of LITA grafts was 5.4±0.7mm². The rate of plaque area was 37.1±5.9%. The eccentric arteriosclerotic plaques were seen in all cases, contradicting the established theory that LITA do not form arteriosclerosis easily. We suggest that IVUS is an effective follow-up device for evaluating the morphological findings and quantitative evaluation of LITA graft in a timely manner.

We tried to identify the risk factors affecting the high mortality rates associated with ruptured abdominal aortic aneurysm (AAA). The subjects consisted of 18 patients, operated on for ruptured AAA, who were admitted to our hospital between 1992 and 1999. The preoperative factors, which were hemoglobin levels less than 9.0g/dl, creatinine levels higher than 2.1mg/dl, type 4 on the Fitzgerald classification, shock state lasting longer than 6h and a shock time index (the time from shock state onset to the beginning of operation divided by the time from complaint of abdominal pain to the beginning of operation) higher than 0.3, were associated with increased intraoperative and overall mortality rates. The postoperative factors, which were bleeding and blood transfusion more than 6, 000ml and an operating time of more than 400min, were associated with increased intraoperative and overall mortality rates. It is concluded that these risk factors were predictors of mortality and it is necessary to operate early because of the risk factors.

We studied the appearance of pleural effusion and inflammatory reactions after endovascular grafting in cases of aortic dissection. From December 1995 to January 2000, 16 patients with chronic double-barrel type aortic dissection (DeBakey type III b) were treated by endovascular grafting. In all cases, enhanced computed tomography (CT) of the chest was examined before operation and at about the 7th postoperative day (POD). Patients were divided into 3 groups. Group P: patients who had pleural effusion before the operation. Group E: patients who had new pleural effusion after the operation. Group N: patients who did not have any pleural effusion. In each group, onset of dissection, patient's age, maximum diameter of dissecting aorta, period of postoperative fever (above 37.0°C), and WBC counts and CRP value at POD 1, 3, 7 and 14 were compared. Four patients were in group P, 4 patients were in group F, and 8 patients were in group N. Period between onset and operation was 41.6±34.6 months in group P, 18.2±27.3 months in group E and 7.3±11.6 months in group N. There was no relation between the effusion and the period after onset. Postoperative fever continued for 5.0±2.0 days in group P, 13.5±2.6 days in group E and 2.5±0.3 days in group N. The period of fever of group E was significantly longer than in group N and P (p<0.01). WBC showed a peak on the first POD in each group. CRP showed a peak value on POD 3 in group P and N. There was no significance among the 3 groups about WBC and CRP, but group E showed slightly high CRP values on POD 7 and 14. No patient had complications regarding respiratory function. After endovascular grafting for aortic dissection, postoperative pleural effusion appeared in 25% of patients. They had prolonged postoperative fever, but there was no respiratory function complication. Endovascular grafting is a minimally invasive procedure with regard to respiratory function.

During a 9-year period from January 1991 through December 2000, 30 patients underwent surgical interventions for peripheral vascular injuries associated with catheterizations. Pseudoaneurysm, the most frequent complication, was seen in 19 patients (63.3%). This was followed by arteriovenous fistula in 6 patients (20%), uncontrolled hemorrhage in three (10%), arterial thrombosis in one (3.3%), and pseudoaneurysm complicated with arteriovenous fistula in one patient (3.3%). We performed repair of the puncture site in 26 patients (86.6%), followed by arterial ligation in two (6.6%), thrombectomy combined with percutaneous transluminal angioplasty and aneurysmectomy in one patient (3.3%) respectively. There was a tendency for patients to have diabetes mellitus or hypertension. Though secondary suture had to be performed in two patients with wound infection postoperatively, there was no other complication. In pseudoaneurysmal patients proximal arterial control followed by direct incision into the aneurysm cavity and tangential finger pressure over the hole in the artery was a safe method to control bleeding. In arteriovenous fistula patients aggressive repair resulted in good outcome. In uncontrolled hemorrhage and arterial thrombosis patients prompt intervention is essential. By using accurate techniques in arterial puncture and adequate arterial compression following removal of the catheter, the incidence of vascular injuries can be reduced.

A 31-year-old man underwent mitral valve replacement because of mitral regurgitation due to continued active infective endocarditis despite antibiotic therapy. Because cerebral mycotic aneurysm was suggested by preoperative IVDSA (Intravenous Digital Subtraction Angiography), cerebral angiography was performed on the first postoperative day. Cerebral mycotic aneurysm was detected in the middle cerebral artery and emergency aneurysm trapping was successfully performed. Although the patient had no neurologic deficit and postoperative cardiac function was stable, impending rupture of the mycotic aneurysm of the superior mesenteric artery occurred suddenly on the twelfth postoperative day. Endovascular treatment using the coil-embolization technique was immediately performed, and the postoperative course was uneventful.

A 59-year-old man with hypertrophic obstructive cardiomyopathy (HOCM) had been treated by β-blocker for 15 years. Since June 2001 the patient has had symptoms of heart failure on sudden onset. Transesophageal echocardiography showed ruptured mitral chordae tendineae. After medical treatment to improve heart failure, open heart surgery was performed and anterior and posterior ruptured mitral chordae tendineae were recognized. Prosthetic valve replacement was performed. Histopathologic diagnosis of the chordae tendineae was myxoid degeneration. The postoperative course was excellent. Echocardiogram demonstrated that the preoperative left ventricular pressure gradient of 55mmHg reduced to 0mmHg postoperatively, which indicated that the left ventricular outlet stenosis had disappeared. In patients with HOCM accompanied by ruptured mitral chordae tendineae, early diagnosis by transesophageal echocardiography and timely surgical treatment are essential for successful outcome.